NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Space View Issues for Hyperspectral SoundersThe expectation for climate quality measurements from hyperspectral sounders is absolute calibration accuracy at the 100 mK level and stability at the < 40 mK/decade level. The Atmospheric InfraRed Sounder (AIRS)1, Cross-track Infrared Sounder (CrIS), and Infrared Atmospheric Sounding Interferometer (IASI) hyperspectral sounders currently in orbit have been shown to agree well over most of their brightness temperature range. Some larger discrepancies are seen, however, at the coldest scene temperatures, such as those seen in Antarctic winter and deep convective clouds. A key limiting factor for the calibrated scene radiance accuracy for cold scenes is how well the effective radiance of the cold space view pertains to the scene views. The space view signal is composed of external sources and instrument thermal emission at about 270 K from the scan mirror, external baffles, etc. Any difference in any of these contributions between space views and scene views will impact the absolute calibration accuracy, and the impact can be critical for cold scenes. Any change over time in these will show up as an apparent trend in calibrated radiances. We use AIRS data to investigate the validity of the space view assumption in view of the 100 mK accuracy and 40 mK/decade trend expectations. We show that the space views used for the cold calibration point for AIRS v5 Level-1B products meet these standards except under special circumstances and that AIRS v6 Level-1B products will meet them under all circumstances. This analysis also shows the value of having multiple distinct space views to give operational redundancy and analytic data, and that reaching climate quality requires continuing monitoring of aging instruments and adjustment of calibration.
Document ID
20150008072
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Manning, Evan M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Aumann, Hartmut H.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Broberg, Steven E.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 13, 2015
Publication Date
August 25, 2013
Subject Category
Earth Resources And Remote Sensing
Meteorology And Climatology
Meeting Information
Meeting: SPIE Optics and Photonics
Location: San Diego, CA
Country: United States
Start Date: August 25, 2013
End Date: August 29, 2013
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other
Keywords
trends
spaceview
climate quality
calibration

Available Downloads

There are no available downloads for this record.
No Preview Available